Summer is a great time for lounging by the pool, cookouts, and other fun outdoor activities. However, it’s also the time when humidity levels skyrocket. While you may attempt to take shelter in the comfort of the air-conditioned air in your home, a lot of homeowners end up asking, “Why is my house so humid with the AC on?”

If your house feels humid with AC running, then don’t take the route of ignoring the issue in the hopes of it going away. When your house feels damp with AC on, this signals that something isn’t functioning as it should and needs to be resolved.

Why is My House so Humid with the AC On? 

Not only is excess humidity uncomfortable, but it’s also bad for your home. Controlling the indoor humidity levels is part of your air conditioner’s job, so when your house feels damp with AC on, it’s a clear indicator that something is malfunctioning.

Here are 4 possible reasons why your house feels humid with AC running:

1. Your HVAC System is Incorrectly Sized for Your Home

If your HVAC system is incorrectly sized for your home, then it won’t be able to sufficiently cool or dehumidify your home. If the air conditioner is too big for your home, you’ll encounter some inconsistencies in the cooling. While some areas of the home will feel cool and comfortable, you may notice others are sticky and humid. An oversized HVAC system will cool your home too quickly to also dehumidify.

If you’ve recently replaced your home’s HVAC system and have started wondering, “Why is my house humid with AC on?” it’s time to check the size of your new HVAC system. It may be incorrect for the square footage of your home.

2. You Have Your HVAC on the Incorrect Fan Settings

If you have your air conditioner on the wrong fan settings, you can easily end up with a home that’s humid even with the AC running. Air conditioners are designed to dehumidify as they cool the air in your home, extracting heat and moisture from the air to make indoor temperatures more comfortable for living. By using a blower, refrigerant, and a complex system of other mechanics, this process is usually successful.

However, you can run your blower fan and motor when the rest of the air conditioner is off. That means you have constant air circulation in your home — and it even sounds like the HVAC system is on — but there’s no cooling. This is a great setting if you want to convert some energy but also want some airflow in your home, but the challenge is that it does nothing to reduce humidity in your home.

When you notice your house feels humid with AC running, check the settings of the thermostat to see if you can identify the issue. See if the fan is set to “on” or “auto.” If it’s set in the “on'' position, that means your blower will keep running, circulating the air in your home without actually cooling anything or dehumidifying the air. If it’s set to “auto,” then you can expect the blower to only run when your air conditioner turns on, which means it should cool and dehumidify your space.

3. The Evaporator Coils are Frozen

One serious issue that could be the culprit for your house feeling humid even with the AC blowing is an issue with your unit’s evaporator coils. It’s not unusual for the evaporator coil inside an AC unit to freeze over during the summer months when the unit is running full blast. This can lead to your home feeling sticky and damp even when you hear the blower running and feel air coming through your vents.

Ice and frost covering the surface of your evaporator coil prevent the refrigerant from absorbing the heat in the air or removing moisture. When the evaporator coil freezes, it’s important that you turn off your unit right away until it can thaw. Running your AC unit with frozen coils can lead to overheating and other pricey problems.

Frozen evaporator coils usually happen because of a dirty air filter, blocked condenser unit, lower refrigerant levels, or a clogged condensate drain. You can prevent them by changing out your HVAC system’s air filters regularly and scheduling an annual tune-up on your unit to be sure it’s cleaned and in proper working order.

4. The Condenser Coils are Dirty

Another common reason your house feels damp with AC on could be dirty condenser coils in the exterior AC unit. These coils are designed to help refrigerants release all the heat absorbed indoors and let it out into the environment. However, when they collect dirt, grime, and other debris, they block the heat transfer and prevent the refrigerant from doing its only job: cool and dehumidify your home.

Keeping the exterior condenser coils clean is the best way to prevent this problem from happening. That means scheduling a yearly maintenance tune-up with an HVAC professional you trust. Your HVAC technician can make sure your unit is clean and ready to keep your indoor home temperatures perfect all summer long. 

Resolve Your Indoor Humidity Issues

Living in a house that feels humid even with the AC running is a sure way to be uncomfortable and irritated. Resolve the problem today. Reach out to CroppMetcalfe to ask any questions or schedule a service visit with our certified HVAC technicians. We can perform a whole-house comfort check to get your AC unit up and running in no time so you can get back to enjoying your summer.